No standard house hold appliance will supply you with any decent parts at all mainly as they have no weight limits and as such have low cost parts that do the job but weigh a ton in comparison to something half decent.

The GR02's have a few problems with them that can cause them to fail. The bearing on the front will help somewhat but if you can support the bearing on the other side too.

Sorry if this is a little blunt but your design is very out dated. It looks very much like a machine from series 1 or 2 from robot wars.

You will not hit anyone with your weapon even with your skirts as Pushbots and Flippers will always be lower. Your weapon wants to stick as far out the front of your machine as you can get away with, without compromising strength and rigidity.

The machine is too long to have a good fast turning circle. Most machines these days are more or less square as you get a good turning speed with great stability. This can be messed with to suit your design. For instance my machine is quite a long way off square if you go by the wheels contact points. Its 294mm Wide and 187.5mm long. But maximum dimensions are 415mm x 345mm.

Stick at 12V or 24V to begin with. If you use lipos then go 3S (11.1V) to 6S (22.2V) is where you want top be looking. My first machine ran 2 voltages (One for the drive and one for the weapon). This was a pain to wire up but meant I could focus the weight more precisely towards specific systems.

Sketch and draw your concepts first and have images that you can look at. As mentioned before, the evolution of fighting robots has developed some very robust and strong designs. Don't feel that you are copying someone as they will most likely have copied someone else but tweaked it for their own needs.

Once you have most of it planned out the move to a mix of Cardboard and Sketch up. Many people (me included) have designed things in CAD that are impossible to assemble in reality. Use the Cardboard to double check your logic.

In order of things to buy... get your motors, ESC's, batteries and TX/RX first so you can test your electronic set up. Remember, you can change the chassis design as much as you like to suit your internal parts, but you cant modify your parts to fit the chassis. (If that makes sense)

I would look at the build diaries of these machines...

-Tormenta and Tormenta 2 (Team Expat) Machines built very well on a budget.

-360, 540 and 720 (all under 360 build diary) Some of the best engineering and design

-Scruffy, very solid and reliable machines using basic parts that you aught to be wary of in the arena

-RogueTwoRobots, Some great ideas and engineering with a range of good machines.

-Team Invade, Current UK champs with Explosion, enough said.

-NST, 2012 Champion, Incredible bullet-proof engineering

My own build diary (Eventorizon) covers a large amount of me designing and building Conkers 1, 2 and 3 as well as our 2nd machine Binky. Most of the questions you will have will be answered in that thread.

(Wow... I am have written a lot)