Suspension wise - the world is your oyster.
On the front You can do anything from a bolt on tele-shock conversion to a wishbone coil-over set up. For something in between, uprated torsion bars and/or anti-roll bars are available
For the rear, axle choice is again a complete open field again. Many use Escort rear axles due to strength, availability of diff ratios, LSD etc.. The Minor axle is ok but half shafts don't have a high torque rating. You can get uprated half shafts if for example you wanted to run a 1.4 K series with a higher rear diff*, this would be ok. The ford axle will of course give Ford PCD - you can get the same on the front disk setup and have Ford PCD all round. Marina axle will have Marina PCD (4 x 3.75"), English axle will have 4 x 4.5" PCD as far as I know. Again it's common to have marina rear axle and Marina disk brake set up on the front with Marina PCD all round (although a more modern Disk brake is easier to get and more reliable, higher rated etc..).
* higher gearing = lower ratio diff.
If you wanted a highly tuned 1.8 Zetec, then you'd be looking for a better axle to avoid the likely hood of breaking the Minor one.
Half shaft strength is related to torque - people often quote power ratings of axles but this is pretty unhelpful - engine peak torque x 1st gear ratio x diff ratio will give you the worst case half shaft torque.
For rear axle mounting & shocks , there are many stages of upgrades. Firstly a bolt on tele-shock kit. These are limited by having dampers at an angle and some are poorly designed. After that there are anti-tramp bars, turreted shock kits and at the top end an axle 5-link set up.
There are a handful of places that will do upgrade parts off the shelf. Quality and prices of course will vary. Depending on how much you can source yourself you can save money, but this adds time tot he project. There have been 5 decades of modified Minors so you'll be able to find plenty of advice on whichever option you are thinking of.
If you want something very good and buy it all off the shelf, it is not going to be cheap - but designing and making decent updgrade parts is not a cheap business.
Running a standard Minor on standard running gear can be done on a shoestring and can be fun. The more you modify, the less of the original charm will be left so there's always a trade off between performance and original charm.
I'm not trying to be negative - just trying to explain. My everyday Minor has 1275, 5 speed box, disk brakes, tele shocks, uprated torsion bars and a very loud exhaust. I would enjoy driving it much more if it didn't sound like a track day car. Getting over speed bumps is unpleasant as it's so stiff, but I can live with that easily as it's stiff in corners
