if i am to get a D16y8 engine for my 7th gen what else am i looking at to get along with it or is this a pretty clean swap? and does the D16y8 generate any more whp than the D17a2 or is it about the same?

The only "Easy" swap for a 7th gen is the K-Series. Problem is that it's a $5-6K motor, and then you're still looking at $3K for other parts like the subframe, and lots of others. Unfortunately, just because it's D series, doesn't mean it will fit.

If you've got the cash, the K20 is amazing, but it definitely comes at a price. The K20A2 (RSX-S) will give you 200hp, the K20A will give you 220hp (JDM Integra Type R), and the K20A3 will give you 160hp (Base RSX/ EP3 si; This one only costs around $1500, but it's still $4500 or so for everthing all said and done. And that's assuming you do the work yourself)

Here's some more info:
http://www.civicforums.com/forums/79-forced-induction-swaps/141122-7thgen-swap-faq.html
http://www.civicforums.com/forums/79-forced-induction-swaps/227132-diy-k20-k24-into-2001-civic-updated-4-29-2007-a.html

I found a forum where you can also swap in a B series engine. can i only do the K since it is OBDII. And is it safe to assume that the K series motors put out more power than the B? Also either way im probably looking 6-8 kfor installation correct?

a b will be cheaper because theyre fairly plentiful compared to a k swap. The K is the king of our honda motors tho, and its 2nd to none.

i have a 2003 honda civic si with a k24a2 i busted my passenger axle and would the stock si axle work or should i use a different one

you need to use the stock k24 axle the A3 doesnt match up, trust me im running 03si with a K20A2 swap and that happened to me

there are only a handful of 7th gens that have any other swap besides a k. go k.