Frozen, you may want to check the details regarding doppler's comments. My replay connects via ethernet so I don't have any experience sharing in-house when using the phone jack. No sense buying gear to share if you can't.
7241252, since you do have DSL the above really doesn't matter since once you get your replay wired in house it will have access thru your router to the internet (or at least you'll set it up that way).
As for a home networking solution... This is an area that is exploding and there are new products and technologies emerging weekly it seems. Fast ethernet, gigabit ethernet, 802.11a-b-g, even 1394b. Given the myriad of choices, I recommend keeping it simple. Wire as much as is possible/feasible as a sort of "backbone" and then add wireless for portable devices.
That means running cable for your replays, your PC and maybe a couple of other jacks for future expansion. You can go as simple as cat5e or as complex as the stuff that has 3 cat5 cables, video and fiber depending on your needs.
All of these cables come back to a "media panel". Go to the depot or www.leviton.com
to get an idea.
You need to decide if you are going to pick up a wireless router or a regular router and a separate wireless access point. I don't have any experience with this but I would lean towards the latter since it gives you more flexibility in placing your media panel in that if you can put both your DSL modem and router in the media panel without worrying about reception. But, wire is wire. You can put your router and DSL modem anywhere you want as long as you run a cable from your router's switch back to a switch in your media panel.
FWIW, I have wired my old house with cat5e which will carry up to 1000 Base-T so there is some room to grow. I pulled two cables (phone and data) for each jack and have jacks in the kitchen, office, next to the TV for my Replay, and by my stereo (as well as other phone only jacks). I have a d-link router that has a simple firewall and DHCP server and 4 10/100 ports. I don't need wireless but if I do I'll just add an access point.
Hope this helps. It is difficult to get specific but maybe this will give you some ides.