He sounds like an excited kid with a passion for fishkeeping, doing his research before buying and stocking the tank, so I see no harm in this.
If you can afford Sterbai's they're the one of the most beautiful ones, as mentioned before, and tolerate higher temperatures. They are stocked in the UK for £5-10 each.
Another popular one, are Panda's, but be careful of the substrate colour with these, and cheaper at around £2.50 - £3 each.
Corydoras are sensitive to water quality, so make sure the tank is properly maintained and cycled. And get at least 6 as they are gregarious (need friends of their own kind).