If the Philips DVDR3480 is the most easily available recorder in Sri Lanka, then yes, you may as well choose it unless you see something much much better. It is very similar to current models sold under the Toshiba brand all over the world: they're OK. The 3480 is an older model no longer sold in the west, but Philips still promotes it in countries that don't require the newer DVB-T digital tuners. The 3480 has an analog PAL/SECAM tuner, so I would assume it uses the standard IEC 169-2 RF connectors. Those connectors are still used in Europe, so I doubt you will have any trouble with your cables.
It is difficult to "recommend" a specific recorder to you: most of the better ones have been discontinued, and today there isn't nearly as much choice in models, so the Philips DVDR3480 may be your only reasonable option in a country like Sri Lanka. The older Sony, Pioneer and Panasonic models were the best, but were discontinued several years ago. The last really excellent DVD recorder with analog PAL tuner was the Panasonic DMR-EH59, a DVD/HDD model still sold all over the world. But it costs triple the price of the Philips DVDR3480.
In 2013, in most countries, the Philips DVDR3480 (or its Toshiba sisters) are the only affordable DVD recorders still available. They are OK, nothing special, the best thing about them is the low price. To get a recorder thats enjoyable to use, you need to spend much more money for something like the Panasonic DMR-EH59. DVD recorders are not like VCRs, where the cheap VCR worked about as well as the most expensive, and the most expensive VCR simply had extra features many people never used. With DVD recorders, the less you spend, the more unpleasant the recorder is to use. The technology is just very different from a VCR: the really nice DVD/HDD recorders were/are very expensive compared to similar VCRs.
EDIT: sorry, I forgot to answer your question about the Philips DVDR35xx models. These are roughly the same recorders as the 34xx series, except newer and usually have analog + digital DVB-T tuners (i.e. DVDR3480 = DVDR3537). The RF connectors should be the same normal PAL connectors as on the 34xx models (if not, RF adapter plugs are available at any electronics shop). If you don't have DVB-T broadcasts in Sri Lanka, you don't need the analog/digital tuner and can use the older analog 34xx models. The Philips DVDR3575 and DVDR3576 were deluxe models with analog+digital tuner and HDD (hard drive), similar to the Panasonic DMR-EH59 I mentioned above, but less expensive. The Philips 3575 and 3576 aren't quite as nice to use as the Panasonic, but they're much nicer than the Philips 3480.