I'm not that familiar with Sanyo DVD Recorders but it's not a brand that I've heard lots of complaints about, they just didn't seem to be all that popular in N. America.
Yes many combos would not output VHS on any output other than the lowest quality composite.
I know Panasonic combos can output VHS on all outputs but on the non HDMI models to get VHS out the component there was a trick but it was explained in the manual. Not hard to do but it didn't default to that.
I didn't talk a lot about combos(VHS player with a built-in DVD recorder) but they were what many people wishing to convert all their VHS tapes to DVD(or a DVD which they'd then copy to their PCs HDD and have it in the digital format) bought hoping to accomplish what they wanted, and were quite disappointed
The vast majority of combos were crap, poor VHS player, poor DVD recorder, just all around cheap. Also people purchasing combos wanted something simple and easy to use but most of the time combos were harder to use and much less flexible. Over in the DVD Recorders forum we've had tons of people who went out and purchased such combos only to post how it wasn't doing what they wanted and they were ready to throw it out the window
IMO your best option is a separate quality VCR(again the vast majority of ones in combos are the $99 bottom of the barrel models) and a decent quality DVD recorder and simply run the audio and video from the VCR(S-video is the best we get in N. America but it sounds like you may have SCART available to you? but as most VCRs don't have S-video out(and some DVDRs don't even have S-video in!) you may be forced to use the lowly composite) to your DVD recorder. Note if your thinking the internal connection from a combo VHS player to it's DVD recorder is quality, your wrong, at best it's composite, most of the time it looks worse(hard to believe there is anything worse than composite but combos sure make it look like there is). Don't ask me why they do this but all combo makers do, you'd think they could have used a quality direct VHS to DVDR connection but again no(although Panasonics to me look like they probably used something akin to S-video).
Again if your thinking a combo will make the job easier you're probably in for a disappointment, trust me I've used both methods. The only combos I can say equal separate components would be Panasonics combos. They used decent VCRs(not top of the line but not junk) and about as good of a DVDR as made.
The best model Panasonics combos(N. American models, sorry not familiar with other models) would be:
the Panasonic EH-75v. In N. America the pinnacle of combos, a quality combo with HDMI output and an HDD for easily editing titles. Note in N. America the EH-75v is quite hard to find and almost always expensive but often times worth it.
ES-45v or ES-46v which is mostly the same as the EH-75v but lacks the handy HDD, still has HDMI out for VHS.
ES-35v similar to the ES-45v but lacks HDMI out(but again you can trick the machine to outputting VHS over component).
ES-30v similar to a ES-35v but one year older. In some ways the ES-30v is my favorite combo(less the EH-75v) as it has dual displays, allowing you to monitor both the VHS side and VCR side at the same time(all other combos ever made by anyone share the display and make you cycle through the remote to monitor the progress of the VHS or DVD side). The ES-30v is an '05 model and getting quite old, often times the displays are getting very dim and hard to read but it's a quality model.
E-75v not to be confused with the #1
EH-75v, the E-75v was Panasonics first N. American combo. Similar to the ES-30v even down to it's dual displays(so actually there were 2 combos ever made with dual displays) it's one downside(IMO) is it switches to 1/2 D1 resolution for speeds longer than 2hrs/DVD. If this isn't a concern for you I often see E-75v's nicely priced.
If you already have a good VCR with S-video or SCART output I'd strongly suggest using this for your conversions and simply finding a quality DVDR. I could give you various Panasonic models or as I've said before some people like Pioneers but I've tried(decades ago) many brands and I found more I disliked than liked.
Lastly, the only Panasonic models I'd not suggest would be the '05 combo ES-40v and non-combo ES-20. These 2 models were the first of when Panasonic switched silicon suppliers and were known to be very buggy, quirky and lacked features found on all other Panasonics, stay away from these!