High resin timber ?

[Blister]

Looking for recommendation as to the best timber to use for external wooden window cills .
I have been quoted over £12K ( 2 years ago ) to replace 2 bow windows , At my age I can't see it worth the investment
I will have a go a replacing 1 cill at a time , One is a 6 panel ( 6 cill sections ) the other a 4 panel, ( 4 sections )
They are both rotten, The previous owner just kept bodging the cills with filler and lots of paint to hide what was happening.
Any advice most welcome.
Thanks.

 

[Eshmiel]

If the colour will suit or you're going to paint them, iroko cills are likely to be the most resilient as the stuff seems impervious to wet, fungus and insect.

Old growth pitch pine with crystalised resin can be quite tough too.

If possible, avoid plantation-grown stuff. Even the durable species are grown too fast with too much early wood and can be much less resilient than the stuff grown in the wild.