Stick with the 2.2 head. It has the exact same sized valves as a 2.4 head, and the ports are nearly identical. Plus, the exhaust ports are a bit smaller and it produces better torque on sub-2.4 litre engines. Plus a 2.4 head costs a ton more....
2.2 blocks have some shortcomings though. The rods are the same crappy cast steel rods that are used on '74-'75 1.9 blocks and all the 2.0 blocks. Plus 2.2 pistons tend to collapse at the skirts. On the plus side, the crank is very strong yet lighter than a 1.9's at around 34 lbs. And early Opel 1.9 forged rods are a direct drop in. So with forged pistons and early rods the shortblock is VERY strong.
The 2.4 block is a good street block. It has a forged steel fully counterweighted crank, albeit heavy at 43 lbs. It has forged connecting rods that are slightly longer than a 1.9/2.0/2.2's, and nice quality Mahle pistons with fully floating pins. This block is pretty strong too, but I wouldn't rev it much past 7000 rpms without stronger rod bolts. Piston speeds are much higher due to the longer stroke.
Personally, I'd build up the 2.2 block if i were to turbo anything, at least for the money you want to spend.
For exhaust manifolds, any CIH exhaust manifold will bolt to any of the CIH heads. For intake manifolds, you will have to either use the OEM Opel 2.2 FI intake manifold (flows crappy though), or cut and weld a stock carbureted intake manifold to fit, or make a manifold from scratch.
Bob