I had a look at Amazon's UK site, and the following MIDI keyboard controllers are within your budget range:
Free delivery and returns on eligible orders of £20 or more. Buy Novation Launchkey 49 MKII USB Keyboard Controller for Ableton Live at Amazon UK.
www.amazon.co.uk
Free delivery and returns on eligible orders of £20 or more. Buy Nektar Impact LX49+ USB MIDI Keyboard Controller with Nektar DAW Integration at Amazon UK.
www.amazon.co.uk
Free delivery and returns on eligible orders of £20 or more. Buy Nektar Impact LX61+ USB MIDI Keyboard Controller with DAW Integration at Amazon UK.
www.amazon.co.uk
Buy Samson SAKGR49 Graphite 49 USB MIDI Keyboard Controller. Free delivery and returns on eligible orders.
www.amazon.co.uk
Free delivery and returns on eligible orders of £20 or more. Buy Native Instruments Komplete Kontrol A49 Controller Keyboard at Amazon UK.
www.amazon.co.uk
There were others, such as from M-Audio and other companies, but the five I linked to are ones you might want to consider. Here are a few comments which reflect my opinions only.
Novation Launchkey 49 MKII -- I have a Novation MIDI controller, but it's a "launchpad" type of controller rather than a keyboard controller. In any case, it's solidly built, and I have a high regard for Novation's products. The Launchkey has synth- or organ-style "diving board" keys rather than "box-shaped" keys like a piano or Hammond, so I don't know if that's an important difference to you. The Novation Launchkey has 9 sliders and 8 knobs, similar to the Nektar Impact, but the Launchkey has twice as many pads as the Impact. The Novation also has two buttons which do double duty as both octave shift and transpose buttons, rather than separate octave and transpose buttons like the Impact has.
Nektar Impact LX49+ -- This is the model you were looking at, so I won't comment on it much. Or rather, any comments I have about it will be given in my comments about the other controllers, by way of comparison.
Nektar Impact LX61+ -- The 61-key version of the Impact is also within your budget range, so you might want to consider it as well, unless you specifically want to get a 49-key controller.
Samson Graphite 49 -- I have no personal experience with any Samson products, but I'm including this controller in the list because one of our forum members (
@John Garside) bought this particular controller and likes it. He might be able and willing to answer questions about it. He posted a good bit about it on the forum at YamahaMusicians.com, which you might be interested in reading:
Native Instruments Komplete Kontrol A49 -- I'm including this one because it just barely falls within your budget range and NI have a very good reputation (at least for their software). My personal feelings about the A49 is that it's lacking the number and variety of controls that the other controllers have, therefore I wouldn't be very interested in it for myself. One thing I like about the other controllers which I mentioned above is that they all have 9 sliders, whereas some controllers have only 8 sliders. I like 9 sliders because they can be used to control the 9 drawbar settings of organ patches. The A49 has no sliders at all.
