I'm selling a zodiac 2.4m slatted floor dinghy- see for sale section. Its a nice good quality dinghy, but not big enough for my purposes. Can be lifted by one person (me, female!)
I've had an Achilles LT-2 for 25 years and it has largely stood up very well, especially fabric and valves. Alu oars were renewed halfways, due to some corrosion and the "hinge" in the floorboards has also needed some attention.
Weight is only some 17 kg – would seem to fit your requirements.
Mine is probably nearing retirement, but I would seriously consider buying the same model again. http://www.achillesinflatables.com/boatmodels/dinghies/lt/LT-2/
If you want a 'blow-up' type get one which tilts up at the bow - much drier and more buoyant in waves ... if a hard dinghy then get one with 2 sets of rowlock holes so that it can be rowed from the bow seat when there are 2 of you aboard.
I second the Lodestar choice.
Came out winning a number of comparative tests over the last couple of years.
We've only had ours for 3 yrs (Ultralight version) but it appears to be very solid, light and has big tubes.