I have a 51 plate Iveco Daily 15S11 XLWB with high roof (2.8 diesel), it's like a tardis! Converted the front section into a seating/dining area which converts to a double bed, partitioned the back off with front wheel frames and takes 3 bikes + all the gear. Put a bed frame on a chain to the partitioned section so the bed sits over the front of the bikes which means it now sleeps 3 easily, lighting and mains etc. Make sure you get some quotes for a van before you buy as insurance companies treat most vans as commercial/trade use, but I use mine as S/D&P + Race Transporter with '4 Counties Insurance' £240/year TPF&T so a big saving. The Iveco is build on a wagon type chassis and is well built so worth a look at one that's been looked after. Engine is nice and smooth and pulls well, just at 90K now but no props apart from rear brake caliper seizing and rear shock absorber.
As can be seen, work still in progress. All sides and roof are insulated with a reflective material to stop sweating (which is what happens if you use ordinary insulation) the cabling 12volts and 230volts were all installed at that stage before the panelling was fitted. Storage units are made from timber framing and MDF and are used for seating, these have a panel at the back seat which drops between the two seats and converts to a double bed. The bunk fits on top of the frame one side and hangs from the roof spar by two chains, hanging over the bikes with space to spare.