Unfortunately the components and labor time make it very cost prohibitive to have somebody do it for you, the only way it makes any financial sense to me is if your capable of doing the conversion yourself. The company we built some evs for only does them for fairly expensive classics so they are not chasing affordability, and for the money u can get a much better ev. With these people ur paying to have a bespoke electrified classic, not necessarily a prectical ev. As the other comment response to you stated a small unibody is very had to convert, and honestly would probably makes more sense to put a more efficient ice engine in. Fwd cars usually have low floor pans so nowhere to put batteries besides in place of the fuel tank or in the engine bay. Then you need to consider how the wheels will get powered, and you start getting into custom machined parts and the cost starts to jump. This is one of those things where it’s a lot easier if somebody has already done it, if your the first on a specific platform your going to have to design ur own systems and parts to make it possible. For example your fwd hatchback doesn’t have a transfer case we can make an adapter plate for and bolt an electric motor to, and most small case fwd transaxles can’t handle the torque of an electric motor so just bolting it to the transmission may not work or last long. It can get pretty complicated pretty quick, not that internal combustion engines necessarily simpler, but the ecosystem they need is already in the car and the cars already been designed around it. Ev drivetrains are also pretty heavy so starting with a small light car is difficult, roll center and center of gravity will be affected, weight added. It may snowball into needing stiffer suspension, larger brakes etc and the car certainly won’t drive the way it did before. Hate to say it but the cost of a custom converversion is likely going to be more than the cost of a slate truck or something lol.

Not the same guy, but I’ve been around a DIY conversion. You can do it to any vehicle you want, but some make more sense than others. Assuming your ‘old hatchback’ is 80s-90s, probably not a great fit. Like he said the whole thing is really a packaging problem, and that’s gonna be rough on a unibody compact. Older, bigger stuff is easier, and I probably wouldn’t bother with something that wasn’t body on frame. The one I observed myself was a 2000-ish Ford Ranger, and that worked out really well. Two large rectangular battery boxes parallel with the driveshaft between the frame rails under the bed, motor in place of engine, controllers etc in extra space under hood. Total cost ~10k, hours hard to guess but a good winter’s worth of weekends