I favour the 2nd choice.

Thomas Gelling (1769-1853) md Elizabeth Kelly (abt 1769-1836) 19 May 1798 Braddan. They had children as follows:
1 John 1799-1886 I think a lead miner of Laxey, md Jane Cannell 1824, 9 children.
2 Margaret 1800-1888 Spinster of Ballanicholas Marown
3 Thomas 1802-1835, md Margaret Quayle 1823 Marown, farmer, 6 children before he died
4 William 1804-1890 Joiner & Butcher, md Margaret Cowin 1831, 11 children,
5 Robert 1806-1845 miner at Laxey, was a widower when he married Eleanor Kinley 1836 Lonan, 5 children before he died
6 James 1808-1835 likely bachelor
7 Elizabeth 1809-1884 spinster but had 2 children by Thomas Lace
8 Edward 1812-1889 Lead miner of Patrick, md Isabella Quayle 1839, 8 children, 4 sons to Charters Towers Queensland.
9 Richard 1815-1843 likely bachelor.

The family lived at Ballanicholas Marown. 1841 census has daughters Margaret & Elizabeth but father Thomas & son Richard are missing. Thomas is there in 1851 with the same daughters plus some grandchildren.

He was one of the four children (Margaret Gelling, Elizabeth Gelling, Richard Gelling & Edward Gelling) who petitioned the 1831 deed of settlement of Thos Gelling & Elizabeth Gelling als Kelly to be the LWT of their mother Elizabeth in 1836, and to be executors.

Isabella Quayle was the daughter of John Quayle & Ann Watterson

1841 census at Ballacrink Cottage, Marown
Edw'd GELLING 25 Lab Y
Isabella GELLING 25 Y
Edw'd GELLING 1 Y
> Ann QUAYLE 60 Ind Y [likely Isabella's mother]
Immediately below his sisters Margaret and Elizabeth at Ballanicholas and two below Henry Gelling an Ag Lab at Ballanicholas who I think is unrelated.

Turning to the other Edward b 1811, son of William Gelling & Margaret Kaneen (md 1792 Braddan, 10 children), Edward was child #8. His father died 1826, mother 1838. He was mentioned in his mother's 1838 Lezayre will as being in America, and not to get an inheritance if he didn't return within 7 years after her death. I don't have anything more directly relating to him.

Edward married Isabella in Aug 1839 which is a year after the above will. Could he have returned from America to collect his inheritance and married Isabella? Possible.

More significant to me is in 1841 Edward & Isabella are living next door to the Ballanicholas Gellings. [By 1851 he's at Cloghiwilley Malew as a Lead Miner, and then to Patrick after that.] At least two of his brothers were miners. Children's naming is a little bit better than the other choice.

I'm confident enough to put him as s/o Thomas & Elizabeth but it's not 100%.