[Mesh] question about replacing comcast modem

I am slowly getting up to speed on networking and want to replace my comcast-provided cable modem ASAP, then set up a tor node and a low power server. Wondering if y'all could recommend a good drop-in replacement from this list or beyond: http://mydeviceinfo.comcast.net/ Marc showed me how to set up port forwarding last night so my 'hello world' site was up for a bit. baby steps... also is there a relatively low power server sitting unused in inventory right now that i could borrow for a month or 2 to practice with? cheers and many thanks, hol