my opinion would be either KE70 or TA22. KE70 for sure will fit your budget, it's a really good car, very reliable, but very underpower too. biggest problem of the car would probably be the rust, and second is the gearbox noise. before i drive the car, my dad used to swap the gearbox 4 times just because the gearbox is noisy, but to me i don't care.
TA22 would cost abit more, but if you look around you should be able to find one, maybe even have money left to paint it with a new coat of paint (same color, cheaper, i did it with my ke70, repair rust + paint around 1.2k). sommore the TA22 will have abit more power to start with because of the engine. if you really fix it up this one is a real killer. struck gold in the future and become rich? plonk in a V8, it fit in just nice. :D