Flat tappet to roller in a roller block

Alrighty guys, i've searched the forums a little and didn't see anything quite like what i'm looking for so here goes, thanks in advance.

What i've got.
87 350 roller cam block from a camaro currently set up with a flat tappet cam Dur@050 ~224/224 unknown lift.

What i'm trying to get.
I'm rebuilding the motor and I'm trying to go to a roller cam. The engine will be in my daily driver 78 firebird so it needs to be streetable. The current cam lacks some bottom end for my taste, though I think the top end is good, so i want to do the roller conversion and go a touch more mild on the cam. I do not have any of the necessary parts for a roller setup (Spider, timing cover, timing gears/chain, etc). I'm also kind of on a tight budget here (~700) but the car needs an engine (it ate a lobe).

Questions I have.
#1 What all parts will I need for the conversion?
#2 Can I just scavenge most of these parts from a junkyard car?
#3 What cars/trucks could I scavenge them from?
#4 The heads i'm running are stock 462624's, any idea on what the lift limitations are?
#5 what would you guys recommend for cam specs?