Don't spend £80 on any of that gadget. Like people already said on this thread, you won't be doing one fruit/veg for long. Basically after 6mo, you can feed them anything other than honey and nuts. Get a hand blender and you can puree your meals for them, saving you lots of effort. If you want a very structured guide, have a look at Annabel Karmel baby and toddler book. You'll see also that you are supposed to move off that one veg/fruit phase quickly to fully flavoured food, but in this case, cooked especially for your baby. Even if you start weaning at 4mo, you'll use it for 2 months max!
And about steaming/boiling one fruit/veg puree, you can look at the same Annabel Karmel book. She actually have instruction how to do it! From cooking, to puree and storing. But basically yes, you use a steamer like
www.amazon.co.uk/Kitchen-Stainless-Collapsible-Steaming-Basket/dp/B0001IWW4I/ref=sr_1_6?ie=UTF8&qid=1349859250&sr=8-6
Or boil it for root veg. Or you can microwave it for things like apples and pears. (They are very fast cooking). Then you puree it with a hand blender. Then freeze them in individual portions with a silicon mini muffin mould, or a specific baby one like
www.annabelkarmel.com/products/make-it-easy-food-cube-tray
This is available in supermarkets, btw. Pop them out once frozen into freezer bag. You can buy inidividual pots to defreeze in fridge or take out
www.tommeetippee.co.uk/product/4_food_pots_lids_4_months_/
Also available in any good supermarket.
I mostly warm up in the microwave, then stir to make sure there are no hot spot, then cool down slightly before giving to baby.
HTH