you could probably fit in ONE bristlenose/bushynose pleco. they come in regular brown patterns or albino
but...with proper tank maintenance, you should not even need an algae eater. they are massive waste producers and that fact alone will severely limit you stocking. they are also more active at night, and hide a good deal during the day...making them rarely seen.
by even just adding some liveplants....even the extremely simple "banana plants" and water wisteria (i leave it floating - - will work as great fry protection if you have enough of it)...these plants will feed off the bacteria that would normally feed the algae.
maybe skip the algae eater and instead think about more fish you may like that will allow you to stock more and will be seen during the day