Hi art - welcome to the forum! I used experians 30 day free trial to get all my credit details for my SOA - they list exact amounts, dates started - everything you need for the form. Hope this helps
The OR knows that the figures won't be exact due to interest and penalty charges. For example, if you go BR declaring £100k of debts and on investigation, the OR finds it's nearer £110k, there won't be a problem.
As Julian says I wouldn't worry too much as long as your creditors details are on your statement of affairs your Trustee in Bankruptcy can invite your creditors to submit their claim for amounts owed.