Also not an accountant! However, my understanding is that, from a PSR perspective, a loan with an obligation to buy is treated exactly the same way as a permanent transfer (ie whether we buy Tel now for £50m or sign him on loan for the remainder of the season with a £50m obligation to buy in the summer, the the transfer fee will hit the books immediately in this financial year, rather than the next one).
A loan with an obligation does get us around any short-term cash flow problems (it is essentially a purchase with a deferred payment), but if we're very tight for PSR compliance in this accounting period (all reports suggest we are), it is unlikely that we have the headroom to be able agree any loan deals that include an obligation (at least not today, anyway).