Congrats on you KE30 purchase. As far as transplant go, should skip it because of budget constraints. Realistically RM10K is just enough for transplant and some issues to iron out. Are you willing to spend so much on a 20 plus year old car? Are you going to keep it forever? You should ask these questions first before doing transplant.
If you do intend to keep the car on tight budget then you could go the simpler way.
A fast improvement would be weber carburetors for your engine. If you swap a 5K from KE70 1.6 could be a good choice. First its quite easily available, penty of stock replacement parts for it. Should be a single carb 5 speed manual tranny. I'm not sure how much it cost. But i presume in the region of a T series engine also. The benefit is you could retain many of the K series engine bay stuff to upgrade to this engine. Like crossmember and mounting points. Though changing them would be better because of higher power.
You don't need to whack any body parts to fit it in too. I recon RM5000 to work on the engine which might cover, port and polish, webers, and total overhaul. But would probably cost slightly more. But thik about it, the engine is just like new! And i remember some guy at DCM using this for drifting, and engine revolutions at 9000rpm!
For a T engine transplant. I would also say NO. And i'm damn well sure. First off, you could have to get a better T series engine from ST and GT series 1975-1980 celicas, Truenos. Or even go about getting one from old TT series coronas. 2T is 1.6cc and 3T is 1.8cc. You need to do some bodywork to mount the engine. Usually some comes with busted gearboxes. As you know T50 is not cheap! No thanks to 4AGE using the same gearbox.
But with 3T series engines you could use old W series Supra gearboxes. Which is also rare and expensive. The only EFI variants from 2T series is 2T-G. If you intend to run weber, you could use 2T-B and 2T-G. When you run high rpm on 2T engines, one thing would fail very often. The distributor arm. I have changed it 3 times in the last 8 months. And that too is some Taiwan made stuff. You would have a hard time finding quality Japan made parts for it. Especially if you intend to look for DENSO ones. You could change it to coil packs or DLI. Which is more work and headache. And not many mechanic does it. The engine is basically a tough nut to crack. But its the little things that are not made for performance driving that is a let down. In the end i'm sure its gonna cost you about RM10K for the job.
As for chassis, you should change all the bushings no matter how nice they look. Suspension mounts, spring mounts, steering mounts, blah blah. See you car corner flatter! Later you might want to invest a little on sway bars and front suspension strut bars.
Don't forget you KE30 should be less than 1 ton in stock from. If your engine is pushing 120hp you would still give problems to modern cars. If i'm not mistaken, your car also doens't have sound proofing tar like mine.
For wheels, i suggest you get something 14x6 or 14x7 where tires can still fit nicely, and you could still drive without worries. You could get 15 inchers. But that would slow you donw a little. And don't forget tire width affects front steering input. Bigger is not always better. If you want to try how a 14" feels like compared to a 13", then i suggest you get a set of 14" steel wheels from toyota Unser. Cheap and you could upgrade to better alloys later on.
For me the checklist would be this,
- Bodywork & paint
- 5K engine and gearbox
- weber
- 5K overhaul
- All rubber mounts
- 14" wheels
- Then start with interior
You would still be paying more than 10K for everything. But the time used to debug problems is shortened. And also there is no side attractions from better ECU, cams, gaskets, more electronic add ons to spoil the plan. hahaha. Which is why i say 5K is the way to go.