Best track tensioners?

[Miggers]

To suit an HL Tiger 1 on standard plastic tracks,wheels,sprockets,idlers,the whole standard
bog-stock factory shebang for about £20($35ish)?

I see there's a few types out there,ones that adjust through the upperdeck grilles,some that adjust from underneath,some that adjust from behind.

What do folks generally use and what's deemed to be a good set for that amount of dosh?
It's my b/day in a coupla weeks(the big five-oh)and I'll have about £20 spare so I
fancy treating myself(and my Tiger of course)to a pair of said tensioners.

Mark