Excuse me it it sounds a daft question

I need to replace both front calipers on my van.
They are the sliding type rather than the twin piston type.
Is it necessary to replace them with the same type of caliper, i.e. are the mounting holes in the alternative types fitted to the T25 the same spacing?
The reason I ask is that replacements of the type fitted on the van are more expensive than the others.
Any advice would be welcome.
Thanks
Andy
