I knew someone who lived in Pocheon for a while and just came to Uijeongbu for the post office, bank, etc. I think it's less than half and hour by bus though. There's a Homeplus to the north and a few Lotte Marts on either end of Uijeongbu too.
Everything you'd need is pretty much right by Uijeongbu subway station (which has just been renovated and is getting a Shinsegae department store in a few months). You'd be going there on their way to Seoul anyway.
I'm sure that your apartment will have ondol and all the amenities you're used to by now. ;)