Hey Dennis, another viewpoint on a few bits;
Body armour - get some and always wear it (ask Rinksy!) you don't need to be going quickly to hurt yourself if you land on a stone or hard ground (not that we have much of that nowadays...) Get something with chest, back, shoulder, elbow and forearm protection
MX Shirt - nice and cool in summer. If it looks like rain (when doesn't it?) a thin waterproof jacket can be stashed in a rucksack (I have an Army surplus one, goretex and whatever, good and light, big enough to go over the armour)
Jacket - you can spend a fortune on pukka off-road gear or go to TSFKAGW (The Shop Formerly Known As...) and get something like a cheapy Oxford bone dry jacket (again, oversized, but that might be a little harder for you to find) and remove all the integral armour panels (they aren't up a to a whole lot tbh) so it'll go over your armour and use that in wetter or colder weather (mine's got a zip-out quilted lining, haven't needed to use that but it could be useful in Winter)
Goggles - you're getting them anyway, wear them all the time. When green-laning you'll spend a lot of time riding past undergrowth, bushes, brambles, trees etc and a twig or thorn in the eye would be serious. Sunnies are not so good to wear as a lot of the time you'll be riding in the shade of trees and going from bright sunlight to dark shade and you need to be able to see stuff quickly when doing that. Depth perception is a little reduced too when wearing sunnies.
Gloves - road stuff is ok but can get very hot. More off-road oriented gloves are more comfortable and getting wet hands is no big deal at this time of year. When riding in Winter it's worth taking a spare pair along in case you get soaked.
Waterproof socks - Sealskinz are ace, they don't feel particularly hot in Summer and are great for keeping feet dry when your boots are soaked. The only drawback is when putting a foot down in water that's actually deeper than the socks are high... :it happens, not such big deal in Summer, can get cold in Winter.
Boots - as said, MX boots are a bit too stiff and unyielding, Trials boots are better, more flex and feel.
Knee armour - definitely worth getting, as are armoured shorts - I have a Knox pair and they give great protection to hips and thighs.
Trousers - MX strides are fine for most of the year, light and comfy, not at all waterproof but they dry out quickly. Worth investing in a waterproof set for Winter, Sinisalo do some very good ones, as do many other manufacturers.
Another useful thing to get is a Camelbak or similar - you can carry waterproof jacket and/or spare gloves, a few snacks to keep the energy up, and a litre or two of water to keep hydrated - I'm forever taking swigs from mine when I'm out. Camelbaks are expensive, but bargains can be found by the careful hunter, either on-line or in sales, and sporting goods or outdoor stores are probably cheaper than bike shops - keep an eye on Lidl or Aldi, it's the sort of thing they may have occasionally.
See you out in the mud sometime then! 8-)
as a result of my mask and glasses fogging up to the point that I was literally blind and there was no stopping because of the bikes coming down behind me. Not something I want to repeat in a hurry 
