[joelc]

Concerning parts, Rockauto.com offers nearly everything for reasonable price and with international shipping. Many European american car owners rely on them.

Concerning the "daily driver" thing. The car is almost 40 years old. keep it in mind that all plastic/rubber parts may start to fail.
On a practical aspect, I would not recommend it if you live in an old town with small streets, lateral parking spaces and/or steep slopes. The car is long, wide and steering radius is rather large compared to euro/asian cars. The car will feel at home cruising on a highway.
I daily commute with my 1992 Seville, 30 km, mostly highway, I get 12.5l/100km mixed. In-town driving only may exceed 20l/100km. Be ready for a very special relationship with your gas station.

 

[joelc]

I don't know about Lithuania specifically, but in most (all?) of European countries, doing engine swaps are either outlawed or an administrative nightmare. The "grey card", equivalent of the car title, lists most of the characteristics as weight, HP, displacement, number of seats, outside colour, etc.
Changing one of these characteristics leads to having the title changed and an inspection will be conducted, you'll have to show homologation certificates for everything that is not stock. And you can't hide it because you have mandatory safety inspections at regular intervals.
I put better brakes (the PowerStop kit with bling-bling drilled/slotted rotors, yeah I know) on the Seville. Nope, no way. Had to buy plain rotors in emergency to pass as the maker did not have a certification sheet that certifies these are conform and made for a 1992 Seville.
So yeah, if OP bites the bullet, he may have to stick to the HT4100.