If you can get a good shave from the shavette, you'll likely have little trouble with the straight razor *if* it's honed well. Less than stellar honing and stropping= more pressure needed= more irritation= bleurgh!

Honing wise, its probably worth getting it done properly at least the first time - you'll he able to see what a correctly set bevel looks like. Honestly, if you get the bevel set well then its not rocket science to refine the edge with finer stones.

3k stone to set the bevel and 8k to refine it shouldn't break the bank and will give a shave ready razor. Obviously, finer stones will finish it even further but an 8k should give a good edge to shave with.