Tall boots or gaiters?

I am old enough to compete in tall boots or gaiters now and am wondering which you think is better. I have finnished growing so I may as well buy something good quality. What brands are best and if you buy gaiters can I just wear ordinary jodphurs under them or do I need breeches? Any advise would be good I'm pretty clueless.

Oh and I do pony club gymkhanas, local shows, dressage and showjumping if that makes a difference.

I have Ariat paddock boot and gaiters and tall boots. My boots and gaiters have lasted me over 5 years now and still polish up beautifully, when I do. I was so pleased I bought some Challenge Field boots from Ariat about 2 years ago and they too are wearing soooo well. Took me about 1/2 an hour of riding to break them in, beautiful leather on them.

I recommend them for quality, keep an eye out for sales, they tend to be a little pricey here in Oz, I bought mine overseas for way cheaper.

I use Devon-Aire tall field boots, they are very nice! & not overpriced.

I am going to buy some soon also :)
I am nearly definate that I want gaiters seeing as they have that little extra give, most people have treadstep ireland ones :)