Official std power outputs :

YBB 2wd 3dr / Sapph 204bhp
YBD RS500 224bhp
YBG / YBJ 4x4 Sapph 220bhp
YBT T34 Escort 227bhp
YBP T25 Escort 220bhp

Power made at std boost approx 8 psi

4x4 manifold is a single piece item - quite compact.
This gives good response and low down torque on lower power cars, i.e. if you are aiming at 300 ish bhp.
2wd is a better flowing design and comes in multiple pieces - better for higher power cars.

Different ECU's are as follows:

Level1 3dr & very early 2wd Sapph
Level6 2wd Sapph
Level8 4x4 Sapph
P8 T34 Escort
Ford EEC-IV T25 Escort

std 205 block is found std on std 3dr and 2wd Sapph
Modified 205 block with thicker walls, smaller core plugs etc is RS500
More than 1 type of 200 block but these are all 4x4 blocks.

The power you will make will depend on the fitment of the other ancilliaries but a live mapped chip, T34 turbo with a .48 a/r exhaust housing and "dk green" 803 injectors would be your best bet for a solid 300+ bhp without spending too much cash.

HTH

Edd