Hi lucie and welcome to the forum
I think that you may be able to negotiate a relocation allowance with your IP - to cover the removal costs and perhaps a six months rental deposit, but it is unlikely that they will agree to allow you sufficient for a house deposit.
If your IP and creditors did agree to leave you with a 10% to 15% deposit fund on top of that, you would probably get high street rates again one year after your IVA had concluded, but I would take specific advice from a mortgage broker on that point to be on the safe side.
Regards, Melanie Giles, Insolvency Practitioner for over 20 years.
For further details contact me at
http://www.melaniegiles.com and view my IVA blog at:
http://melaniegiles.blogs.iva.co.uk