$10K can go by very quickly.
I'm putting together a couple engine option lists together, because I'm going to do something major to my engine in about 6 to 12 months. The costs for the engine and tranny alone can cost $10K, if your looking at all brand new stuff.
Check out my suspension stuff (some bushings and whatnot are not listed), cause I've spent about $1,500 or more so far. My brakes were another $1,000.
A g-force T5 would only cost between $1K and $1.5K.
Shortblock or longblock? CHP's 347 is gonna cost me $6,500 (complete engine)
Supporting hardware for the engine could be $1,000 easy for new stuff.
Labor? For me it is necessary.
Goals? That could raise the costs substantially.
My other option is basically getting my stock engine rebuilt (probably to a 306) and slapping on a Kenne Bell with a custom strut tower brace. I need my stang to be a daily driver that can pass emissions and have a new/rebuilt engine that can last 100,000 miles. Power just needs to be over 300 rwhp. The main problem with the rebuild option is finding a reputable local shop that will get the job done right the first time so that I end up with a reliable engine.
My suggestion would be to do some basic suspension upgrades and get better brakes. Subframe connectors that weld in are a must. This will improve the safety of your car and be a good foundation to build power on.
Without even mentioning specific engine parts and combos, it seems that costs can get out of hand quickly if not planned out well.
I've thought about the T56, but I just don't think I'll need it. If my wife ups my budget later on, maybe, but the costs go up, cause I'll need a new driveshaft and other modifications, let alone the cost for the tranny itself.
Let us know where you're interested in putting your dough.