Hi lf and welcome to the forum
An IVA will not affect your visa, but I am not sure it is the right solution for you, as you would be paying in £15,000 over a 5 year period and only owe £17,000. If you were to extend the repayment period by one year, and persuade your creditors to stop charging you interest, you would repay the debts off in full and your creditors would avoid having to fund the costs of an IVA.
Regards, Melanie Giles, Insolvency Practitioner for over 20 years.
To have me propose an IVA for you, please visit:
http://www.melaniegiles.com/ivaEnquiry.asp
See customer feedback at:
http://www.iva.com/iva_companies/IVA_Advice_Bureau.asp