Iâ€™m not aware of anyone other than hard money lenders when you have a large down payment. Credit repair is a good step, but you are wise to be careful. Most of the legitimate steps you can do yourself, but it will take some time.
Where your situation is driven by an ex-wifeâ€™s BK, it may make sense to talk to an attorney who handles credit repair and see if they can provide some hope.
Apart from that, pay down any revolving balances to 1/3 or less of the credit limits. Dispute any inaccurate data to each agency that reports it, but especially your middle and upper score reporters. Pay everything on time, don't close any accounts or pay on any old collections until instructed to.
If you have a lender in mind, ask them for more advice on credit repair or a referral to a legitimate credit repair company. Best of luck.