Scottish koi club

Thinking of a new pond for next year by adding some height with adding sleepers. then a nexus 210, bottom drain a skimmer to a easy pod and an home made shower for the summer about 1500 gallon and a liner. would the filters be okay. and would a bottom drain and skimmer be easy to fit with a liner.
Thankz Alex.

this is my pond at the moment 1000 gallons a big box filter 25v uv waterfall and skimmer small box filter added for summer and about 6 koi.