Dont decide too fast, coz im too driving 4G61 NA, pls check how many 1/2 shops having this 1/2cuts, frm there you can find out abt parts availability. Dont just see the Plug and play concep for Iswara/Saga, coz there is no such thing, you still need modification but minor. If you asked me i would recomend you any 4G9xx series, reason y, newer models, parts availabilty, reasonable price, low mileage and so on. If you want to know abt more you may can check my prevoisly posted threads about my breakdowns. I wouldnt say its worst enjin, its just somting like almost obsolute most of the parts for this models, u may mix n match with 4G6xx serius but believe me it will be hazzle.
Its just my experience before.