best engine swaps for ta23 celica?

[Zr76-ta23]

I've  just bought my first car being a 1976 Celica Ta23 and being completely new to car restorations/rebuilds, I'm in great need for good car advice. Only being 15, I would really appreciate some help on what are some of the best options for engine swaps as the current motor has clocked over 800,000kms. I'm looking for something newer that's more efficient and performs better but still being a 1.6L-2.0L four cylinder engine, that doesnt require too much heartache in installing. I would also love some advice on whats involved in doing such swaps in regards what extra parts/changes etc required. So far I've been researching 4age and sr20det engines but am lacking a good insight into what is the best option for me regarding my current circumstances. 

[trentmeyer23]

I would personally aim for something like a Beams 3S-GE.