They are easy to get skidding, they are difficult to keep going though as the chassis makes them twitchy as a rabbits nose.
Get the diff welded, put in about 45-50psi on a dry day, and 40ish on a damp or wet day, get a decent seat and harness, and jobsagoodun!
My MK2 was one of the most fun cars I have ever owned, even with the cheapy coilovers, it handled like a brute, and when you got it sideways, it was a treat to just keep the back end hanging out.
If you do more track drifting stuff, you will need to clutch kick it a fair amount on transitions. Don't bother with a hydro, you won't need it while still using the 1.6. Add some lock collars to the steering rack for some extra lock, this gives you more angle, allowing you to keep the powerband up. Get a 5Race cage which bolts in to some nice easy positions without having to chop into the boot firewall.
Go for an Excedy Stage 2 clutch for general abuse, they last a good time and will take a hell of a lot of action, they're also good should you want to go boosted.
Talking of turbo's, check out Skuzzle Motorsport. Stu was one of the first guys to boost an MX in the UK. He went the way I was going, with a T25, uprated fuel system, and using the OEM ECU with an O2 switch. Also look for a guy on YouTube called - The Car Passion Channel, Greg is an absolute genius with his cheaply boosted Miatas. He's just done one called "Broke and Boosted" which uses the OEM ECU setup, he did it all for under $1000. If you know a fabricator, you can do a good boost build for about £500, this will give you around 150bhp at the wheels.
Hope this all helps bud, gimme a shout if you want any more help.