Turbo recommendations

Something like this would work nicely, IMO. The turbine housing is a little big for what you're doing but it should still spool up nicely. Very common turbo for 4-6 cylinder turbo builds. It comes with both water and oil cooler ports, but only oil is needed. You can plumb it for water if you want though, the extra cooling certainly doesn't hurt.

http://m.ebay.com/itm/270940682667?nav=SEARCH