You should be able to get any phone you like on that contract... Most the expensive ones should be free, however you should try going through to the contract cancellations and ask for your porting code and they should be able to do something about your line rental too or at least give you some more minutes.
I have some examples below
Contract 1, £25 a month cant remember number of minutes, line rental reduced to £20 now on 500 mins and 500 texts and a free N95 (when they were new)
Contract 2, £30 a month, 400 mins (I think), line rental still £30 now 500 mins and unlimited texts + Nokia 8800 Scirrocco (when they first came out) for just £49.99
^ This was a great deal because at the time, if I had given the same phone to myself from our shop, I would have had to pay £399 for the phone...
Contract 3, £20 unlimited texts, I was after the N95 it was costing me £200 on the same contract, upgrade department told me they would give me the phone for £150 on the same contract. Cancellations, gave the phone for Free and reduced my line rental to just £7 £7 unlimited texts and the N95 free
My recommendation, is to look for the expensive phones as Orange usually really do look after their customers, even if you dont like the phone afterwards you could always sell it. The phones that sell quite well at the moment are phones such as the Samsung F480 which is very new out and is identical to the Samsung Armani, they have just removed the Armani branding and fixed the bugs, its a decent 5 mega pixel phone equivalent to the viewty just better because its not an LG, lol and its better than the 2 mega pixel Iphone. Pay as you go price £260+ The standard N95 is also good and you might be able to get a good contract offer with it too as its cheaper in price to the 8GB version, its great all round phone which you can have sat nav on. Pay as you go price £200+
I always look on ebay see which phones are the most expensive and which ones sell well before I call Orange so I know even if I dont like the phone, I know how much I can sell it for. I would keep away from LG as they dont really hold their value, Sony Ericsson are good but there is nothing out by them which has any Wow factor. Also look on T-Mobile and the other networks and see which phones they are doing. As an example on contracts and minutes Three have a great offer with 1100 mix and match minutes or texts at just £27 mention that when you call