My last car was an MG ZR 160 (VVC engine). I planned to swap for the landrover head gasket too as it's a common upgrade on the MGZR forum. (I'm trying to convert one of the guys there to follow in my footsteps and get a Coupé, he was looking at a Cougar so I'm trying to steer him here instead - funnily enough I was looking at a Cougar after my MG too lol).
The main plus of the K-Series is that it's remarkably light, and really "revvy" but to make it light there was something to do with bolt lengths and other stuff I didn't understand, but basically what made it so good was also it's downfall. Yes Lotus used the K-Series engines for some time before turning to (I believe) Honda?
Anyway, my MG never had a problem with it, as long as you let the engine warm up properly before revving the tits off it they usually last just fine. Some will go regardless but some have been known to do plenty miles and never fail. That said I've known someone that had one fail about 4 times - once it's gone and been skimmed and replaced it's more prone to going again you see.
People do make out like ALL MG/Rover engines WILL get HGF after 5 minutes of owning it, and it's not true. It's more common, and their main flaw, but it's like saying ALL old Fords will need new gearboxes and clutches as that's their most common flaw too. All manufacturers have a main issue, no car is 100% perfect, MG/R is just more famous for being bad because it's greedy investors milked it dry and let it fall down the pan, and the workers with it. So what if they bought the company for £10 (I seem to recall that this is really the price they paid for it) that doesn't mean they can give themselves bonuses that ran into the millions each, as well as to their girlfriends/wives etc and let the last well known British car company die on it's @rse!
Everyone should own an MG at one point though, the ZR (especially the 160) is a hell of a lot of fun to drive and faster than most hot hatches that cost 5 times as much. Plus a fair few people put an old Rover T-Series turbo engine in ZR's so they don't suffer HGF and they have a 2.0t with 200bhp as standard (seen these modded to 320Bhp).
Search eBay for MG ZR Turbo and some will always be around lol.