The 6kg bottles are the same size as the calor bottles.
After 2001 vans had fitted adaptors for gas.
The one you want is this one -
http://www.thegaslowcentre.co.uk/magent ... utlet.htmlThat's the two bottle version. The important bit is the pushover fitting for the gas hose, so make sure u buy one with that fitting.
Also, depending on the height of your gas cupboard, u should consider the 90deg bend fitting for the top of the bottle(s). But being an autosleeper, should be ok.
My setup is 2x 6kg bottles with braided hoses, the manual pre-01 adaptor and the external filling point + all 3 adaptors for LPG guns. Between uk, France, Portugal and spain I used all 4 fitting types. My previous van was an auto sleeper amethyst and could only fit 2x 6kg bottles, but my current van could fit 2x 11kg bottles with some small changes.
Whether you go for the braided hoses is up to you.. they are more xpensive but i plan to use my system for many many years to come... also how you fix your filling point should be condidered before u purchase. I always put it on the exterior which means cutting holes... you can get a bracket to fit it inside the gas locker or some other place... max length of filling hose connector I think is 1.5m.
I did all my research online, got the best prices I could for everything and then spoke with a local place to match the price + a bit less for forgetting the receipt.in the end, all in cost me 370 with the trimmings , cheap compared to the vat receipt version. Fitting is free if u do it yourself
For reference, 1 6kg exchange bottle will cost:
20-25 € per bottle for initial purchase and replacement agreement (refundable when u bring bottle back with paper agreement)
25 per bottle for exchange.
Also assumes they have a bottle thst fits the puny english gas lockers of the 90's vans. Only 1 french bottle fits, the cube which is a rare one... no Spanish bottles fit and there a is a very rare Portuguese bottle that fits.. just.
To refill both of my 6kg, it costs me between 15-17 € (0.6 - 0.8c p/litre) total.
I find living in portugal very accommodating. If you are willing to learn the language, then the people are always interested... but even if not, a lot of them speaky the English and want to practise. I give them my best Gloucestershire accent if they insist on talking English

I don't use campsites at all, but I would think your van lacks a shower and perhaps even a seperate toilet compartment? Definately get a toilet! Met soo many ppl in smaller vans without... public toilets are not exactly widespread here... shower not a big deal if you are here during summer.. any beaches with tourists have showers and water is available easily without paying the devil campsite owners. I use a solar shower bag during summer (also during winter too sometimes, today was 23c) and several 5 litre bottles out in the sun for hot water. No point wasting gas. I used to think it was improper to use the solar shower in public, but its not uncommon to see people showering naked in beach carparks... and even inthe centre of towns... so now I say when in doubt get it out

Livin' in me van in Portugal.
'93 Mk4 TD 150L Hitop Custom Camper
100ps Epic blue spot