The 1.3 is an interference engine, which means the valves will smack the pistons in a chain off incident.
Repairs mean head off, check for damage to pistons, valves and in extreme cases, the crank shaft!
The rebuild would involve gasket sets, valves, possibly pistons and shell bearings, as well as new oil, filters, coolant, chain set and so on.
I would rather look for an engine from a smashed van/car and simply replace the chain set, oil, filters, coolant etc. You could save a considerable amount of time and money.
But insist on hearing the engine running before parting with your hard earned
That's just my take on it, there is plenty good advice to be had so it's up to you.