2L type 4 (914) rebuild options

[VielziDub]

With regards to my 2l Type 4 engine GB-code out of a 914.
I have a good bottom end and good heads but need to get replacement bits to fit between them! (I.e Bareels and pistons)

I like the idea of a bigger engine but would be quite happy with 2 litres of displacement as long as I can keep the compression to above 8:1 (preferably nearer 9!)
I beleive that in original stock form my engine ran domed pistons (Euro spec 914) with a high compression (10:1), but cannot find replacements anywhere, so it looks like I will have to make do with flat pistonjs. Anyone any idea where is the cheapest place to get 2 Litre replacement B+P's (to the UK!)?
Can I increase compression again my skimming the heads?
Or can I recover some of this compression by using larger displacement B+P's? How much machining required?

I know there's a lot of questions here but I am struggling to decide so would appreciate some input.
Cheers folk!
Dan:coffee: