carkid

I have a 1999 Legacy GT with the 2.5L EJ25D (dohc, phase 1) and I want to swap the heads. Now I know that I'll need new 2.2L heads with dual port so I don't need to change my exhaust, and I've read that you need a new timing belt. (Donor car will likely be 1995 Legacy 2.2L) Now here are the issues: - Do I need to use the 2.2 head cam sprockets or can I use the ones from the 2.5? - Besides the previous question, do I need anything else other than the 2.2 belt for the timing system? - The bolt pattern for the 2.5 manifold I have has bolts in a straight line, however the 2.2 heads I've seen (1995 and older) have diagonal bolts. - Can I use the 2.5l head bolts? I have a new set which I will use. 14mm 12 point. - Is the bolt pattern the same? My current one has 6 bolts, 3 on top behind the top cam, and 3 down low behind the bottom cam. - If the donor engine (2.2L) didn't have HG issues should I still get the heads planed by a machine shop? - Should I get new valves seats/guides/valves/springs or is that overdoing it? Pics are here (2.5l head, block and manifold): http://imgur.com/a/ExhsZ