Newbie advice please

Hi All

I currently have an old Specialized Globe hybrid bike that I use for a bit of commuting and with the kids but now I am thinking of getting a road bike. I am toying with the idea of trying a triathlon, but would also use the new bike to commute to work (approx 10k) and maybe get a turbo trainer for some indoor winter training too. I don't want to spend too much in case I don't take to it and have read a number of reviews but wanted some help from people who are more independent.

I can get a bike through the cycle2work scheme, but this is limited to Halfords - they can get the brands in, but I think they would do a better deal on their own stock - so the options I have there are:

http://www.halfords.com/cycling/bikes/road-bikes/boardman-road-sport-bike

http://www.halfords.com/cycling/bikes/road-bikes/boardman-road-sport-lim...

The other option I've seen in the B'twin from decathlon, which I won't be able to get on the scheme, but I have heard good things about.

http://www.decathlon.co.uk/triban-500-se-road-bike-black-id_8306187.html

So do I spend more, but benefit from the scheme or spend less but not benefit from the scheme? Any thoughts would be very welcome.

Thanks in advance