Neuro,
I've done some poking around and IRF has made a revision to the TO-220 packaged MOSFET you have used. I think it is now possible to shrink your design by 40%.

Check it out
IRL3705NS/L
IRF4905S/L

Only a little difference between them in the Thermal Resistance.
Neuro check it out if you can I'm waiting for mine to come in. Feel free to comment if you found anything wrong with these Fet's.

THX ahead of tyme