Recommended leisure battery for Duo?

My fitted leisure battery is a Bosch LFD90 and it needs replacing. I would like to do a 'like for like' replacement, i.e. another lead-acid battery and not try going down the lithium route at this time. 

Our use is a mixture of sites and Aires, about 50 / 50 and we have a 100 watt solar panel fitted. Trips away (in these Brexit, maximum 90 day times) are limited to circa 45 days abroad and about 14 days in the UK

Please can I have some suggestions for the best model that will fit under the driver's seat?

I have Platinum from Tayna, my last one lasted at least 6 years (it was on it when I bought it) so went for same again. 110amp I think.

In your Warwick, I assume the battery is under driver seat?

If so, measure it carefully, then go to the Tayna website get into leisure battery.

Then get the highest Ah SLA or AGM that'll fit. Be sure to get terminal placement correct.

The battery on my 2015 Duo is under the offside bench/bed seat.

I replaced it at 15 months as it failed with a 100a lead acid and it is still going well todate. Mind you it is always charged with solar and MPPT and never need to use EHU when at home.

PS Sargent shut down when parked up and van not in use.

Thanks to all for the suggestions and advice,