R30 Upgrade

[seanr30]

Hi all - can anyone advise me on what is the best motor to buy 2nd hand that will go in fairly simply into my 1983 R30 hatchback 2.4 E. It currently has , as you probably know, the 2.4 six, with an auto gearbox (3 speed). I'd like to put in a bigger motor and manual gearbox combo - is there anyone who knows these things , that can advise me of

a) the best motor / gearbox combo, and;

b) where I could purchase these.

Many thanks