Tyre Advice for RTV

I know I may be opening a can of worms here and tyres are a total mine field. But I'm starting doing some RTV with my TD5 90 Defender. it only has AT tyres on at the moment so I'll keep those for general running around and keep the mud terrains for off road.

I looking at 235/85/16 are those the right size to be looking at?

I was thinking either the Fedima Sirocco or insa turbo special tracks (links below)

http://tyresdirectuk.co.uk/shop/product ... =&id=16723

http://tyresdirectuk.co.uk/shop/product ... =&id=16259

I was also recommended these below but I'm not sure if they are aggressive enough for RTV

http://tyresdirectuk.co.uk/shop/product ... =&id=17321

does anyone have any advice on which are better. I know they both have the same tread pattern but the Sirocco's seem to have more tread on the tyre walls. but I wasn't sure if the Special tracks were better made?
Sorry if this has already been covered I'm just not sure which to go for.

op2:

find another link and you can try one of each type on each corner simples

ha Thanks I know it's a difficult subject I could't find the answer in searches and have a limited budget so I want to get the right tyres. So advice will be gratefully received.

my mate ran insa turbo dakars 265/75/16 on his fender in the rtv trials

These'll keep you goin'

235 85 16 RECIP MAXI 3D MUD Terrain tyres only x 4 | eBay

I run 7.50x16 Kingpin hilanders for rtv trials, there like the old diamond pattern but legal to use by the msa rulebook. I've found them to work v.well in deep mud and also on side slopes where directional tyres lost there bite.

I've also used special tracks 265/75 but these compromised steering lock and my km2s 255/85 which I use everyday while still being excellent on certain trials mainly woodland lost there bite in deep clay mud and caused a loss of traction

I know a lot of rtv people and they all run on insa turbo special tracks

235/85R16 112Q Malatesta Kaiman Tyres order online from Tyres Direct

I has these on my trialer, exactly the same tread as the fedimas but abit £20 a corner cheaper and have softer sidewalls, in my comps guys generally have the siroccos those on the class above and Insas in my class, but I haven't seen mine being any better or worse so far but I prefer them as the sidewall lugs have got to help in deper mud/ water