Are all your products in stock ?

Yes. For each produt, stock level is clearly indicated on the top-right part of the screen. When out-of-stock, the re-stocking time is mentioned just below.

Can this drive a 2x12 cab at 8ohms ?

Yes, absolutely.
You have two options: either use your 2x12 cab as an additional cab and keep using the mini amp's internal loudspeaker + your 2x12" cab, or you replace the mini amp's internal loudspeaker with your 2x12" loudspeakers.
Depending on the option, you either have to purchase a specific 'complementary cabinet connection cable' or a 'replacement cabinet connection cable'. More details on these cables here:
Thanks for your question and don't hesistate to come back to us if you need any additional info.
Have a great day.

Do I need a line output or a DI output on my guitar / bass amp ?

Using a microphone is an easy way to play through a PA system or to record your instrument.
If you wish to use a DI box, it is not necessary to have a guitar amp or a bass amp with a line output or a DI output. There are excellent DI boxes with two outputs available on the market such as Radial's StageBug:
On the StageBug SB-1, connect your instrument to the "INPUT" jack, then connect the PA or recording equipment to the "OUTPUT" XLR connector and connect your guitar / bass amp to the "TUNER" output.

Does the Bass amp come with a UK three pin plug?

YES, all our amps ship with a 3 prong UK plug.

There is a 'UK 3 Prong' version for each of our products which can be seen through clicking 'PRODUCTS' in the TOP Menu, and then 'Amplifiers'.
As an example, here is the direct link to the UK plug version of the 06B400 Mini Bass Amp:

GSS 06B400BH: As I read it, this amp has two 100W outputs that run each with a minimum of 8 ohms. Is there a possibility to run this amp bridged with 200W into one 8 ohm cabinet?

Each speaker output of the 06B400BH is already driven by a bridged amplifier module internally. So the two 100 Watts RMS speaker outputs cannot be bridged together to form a 200 Watts output.
The only possibility to get 200 Watts into a single cab is in the particular case of a cab loaded with two 8 Ohms speakers: in this particular case, one can get the 06B400BH to drive each speaker of the cab with a separate 06B400BH output. This is what we are doing with our Double8c combo (Double8 cab sold as a pack with a 06B400BH mini amplifier head).

GSS-06B400 GH 50w head used with GSS-08GC200 Speaker enclosure do you have any demo's avaiable used with hollow body and semi-hollow( epihone dot, ibaneaz as73 etc)also used with say solid body telecaster for different styles, jazz rock etc

Here is a pure jazz play test of our Top selling jazz amp: the GSS 05G200SJC Jazz Cat:

Mark Rouve is playing a nice Hollow Body on this one: please feel free to jump start from 14:40 to avoid the long interview in French which takes more than half of this video's time.

The 06B400GH guitar head is the one used on the Jazz Cat mini combo.

Here is a second video that shows our mini tube guitar head, the GSS "Tube Sandwich" tested together with three of our cabs: a 12" ultra-lightweight cab (10 pounds) loaded with a Celestion G12M Creamback Neo, and then an 8" cab (GSS 08GC200) and a 5" cab (GSS 05GC100) in the second part of the video:

Mark Rouve starts this test palying blues-rock style with the 12" cab. Then he switches to the 8" 08GC200 from 7:39. Finally, he ends the test with the 05GC100 mini cabinet from 10:55.