There are a few notices in the newspapers for Joshua COLLIER, eg:
"MARRIED ... On Wedndesday last, at St Martin's in the Fields, Joshua Collier Esq, to Miss Sykes."
Morning Post, Friday, December 3, 1802
Putting their marriage on 1 Dec 1802.
"DIED ... In Mark-lane, on Wednesday last, Miss Caroline Kendall Collier, fourth daughter of Joshua Collier, Esq., of Havre de Grace, aged 17."
Morning Chronicle, Saturday, May 12, 1821
"MARRIED ... On the 11th inst., at Charlwood church, Surrey, David Charles Porter, Esq., of Park-place, to Frances, youngest daughter of Joshua Collier, Esq., of Old Lands, Surrey."
The Times, November 13, 1822, Issue 11715, p.3
If this is the same Joshua Collier (oilman, of Mark-lane) he was also bankrupt in 1793 and 1800.