I forget whom but somebody on here came up with the idea of adding loops, like belt loops, to the sides of kecks to feed knee pad straps through, to stop them slipping. I haven't got around to it yet, but I intend to.
Viper or British Army Northern Ireland gloves are good allrounders, IMO: water resistant leather, padded on the back, do up at the wrists so they'll not slip much, sorta warm... but the padding doesn't protect against hits as much as you'd imagine. Not to be a wimp or anything, but a close range hit on the thumb knuckle hurt so much it pretty much paralysed my thumb for a couple of days, and that was through Kevlar & Pyrohide gloves! Leather gloves make it difficult to do anything fiddly also.
Still, I'd recommend the Viper's for cold/damp/wet weather, as a good bargain, and the type with plastic armour on the back for summer - you can get them fingerless, but probably better to cut just the tips off a full fingered pair. Even with the tips in place they are easier to feel through than leather. If you get concerned about protection from pyros and can't afford Pyrohide, you can get fire resistant AFV crew gloves for less than a fiver on fleabay, but they're probably not much use on their own.