if you arent willing to take on the loan as a personal loan, not sure why not, but if your worried about not be able to pay it back, then using the vehicle of a limited co to avoid the repayments is not a good reason for being a limited co in the first place. May have got this wrong but I am fed up with companies disappearing and reappearing later down the line, debt free!
If your in business and you want to expand you normally need to borrow the cash, the risk is you may have a bad year and risk losing the business due to debt. Only you know whether to borrow or not, but imho far too many out there go and borrow for new vans etc and dont realise they dont have the cash flow required to make the repayments. The banks dont mind, they will just take your house if you own one and flog the van.
From what you said, you are looking to build property as well and want the money/loan available for that, looking in from the outside Id do the build and forget a van upgrade, it could be the strw that breaks the camels back if yr not careful.
The other issue is that as a limited company, you used to be limited in the losses that could hit you as a director. Nowadays thats changed a bit and directors can be taken for a lot more than they realise as a limited co, but its still worse for a bank to lend to ltd companies hence why they sometimes show a lack of interest!