Hi Nicola and welcome to the forum.
I am sorry that no other forum expert have picked up on your post since 19th April. I have been away on holiday.
So long as none of the debts in the limited company have been personally guaranteed by you, then they will be unaffected by an IVA or any other form of insolvency you may decide to pursue. The limited company will need to show it can pay you sufficient salary to sustain IVA payments, and therefore company cashflow projections will need to be produced to support this. Apart from this, there are no other real implications for you.
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