First post; please be gentle

[GTSPhil]

Hi Christiaan

Good luck finding a nice mini in our country.

First off you only need 3 things to make a classic mini reliable enough to be used as a daily driver.

Electronic ignition kit.
Disc brakes in front, depending on wheels you run
7.5 inch Cooper S brakes for 10 inch wheels
8.4 inch GTS brakes for 12 inch wheels
VW golf conversion for 13 inch wheels
Upgrade the cooling system either with new 3 core radiator, Minispares hi-flow 2 core or if needed and budget allows all alloy radiator.

The obvious thing many new buyers miss is that the numbers on the papers, must match the numbers in the car (engine and VIN number).

Budget depending the rest is done in stages:

Nice power upgrade that is not too costly Stage 1 kit which will consist of:

Ported and polished head, either a "new" one already done or have this mod done to the current head.
Nice LCB with free flow exhaust.
Depending on carb a proper inlet manifold.  If you use SU that came with the car, that can be modded too.  This will need change in needle.
Some performance air filter with ram tubes (K&N the obvious choice or else pipercross or the like)

Next up lighten the flywheel and backplate assembly.
Opt for either a nice cam (if the engine is going to be opened up) or 1.5 ratio rockers any brand/make will suffice.

If you are going so far, close ratio box with a change in diff IF NEEDED.

As far as pricing goes that will vary upon either new or used items and if sourced from where (a specialist or private seller).

Cheers

PS the more modded and tuned the engine the more braking and cooling power will be needed and then the discussion starts for reliability.....