Garage Racking

Tomos, have you thought of these I have them in my garage easy to install and you can alter the height of the shelves by unclipping the brackets anytime you want I also have considerable weight on them

 

You can get brackets up to 610mm in length.

 

If your going down the timber route, take a look at CLS timber - or stud timber
Incredibly cheap and without knowing the technical properties of stresses and loading and weight handling, I'm pretty convinced it will do the job
Available in various sizes, treated also, here's an example from B&Q, even cheaper if your buying 20+

Its great timber, get the odd twisted piece but if your picking it up yourself, can check each length
Although generally used for building stud walls, it has loads of other uses and I never understand how its so cheap
Guess its also worth checking prices at local timber yard

http://www.diy.com/departments/cls-timber-t38mm-w63mm-l2400mm/27507_BQ.prd

 

Tomos....I found the strongest and cheapest way to provide shelving was with this design.
Have done it in two garages. One last week.
You can set the shelves to your needed heights.(max storage.)
fast easy and reasonable looking.
50x50 uprights.
25x50 shelf edges.(all perimeter)..screwed through to 25x50 with drywall screws...250 spacing (no loading)
11mm OSB cut to 400mm x 2400 (3 per sheet..no waste)
Obviously you can amend materials sizes to suit loadings.

RS