The Bugis were originally from South Sulawesi, and their cousins were the Toraja people, who had actually the closest linguistic links with the Bugis, and the Makassar people, who shared the closest physical proximity with the Bugis so much so that many people used the words "Makassarese" and "Bugis" interchangeably. Though some people may have read that the Makassarese from Goa were constantly fighting with the Bugis from Bone for supremacy, sometimes in league with other Bugis kingdoms who do not want a strong Bone dominance over their kingdoms.
If I remember correctly, in 1669, the Dutch destroyed the Goa power and turned it into a Dutch controlled port, which is part of their monopolistic trade network in spices and ther natural materials of the archipelago. From that date onwards, the spread across the archipelago, creating a Bugis diaspora, especially in the Western side of the archipelago, since the Eastern side near the Maluku islands were controlled by the Dutch.
The Bugis featured heavily in court intrigues and politics on the Malay Peninsula and on Sumatra. They can be found on the Eastern side of Sumatra, all the way up to Acheh. Some Bugis went to Kalimantan, even before the fall of Goa. Some Bugis even went as far as Papua and Cambodia.
The Johor-Riau empire was half Malay, half Bugis, with a Malay Sultan and a Bugis YTM (Yang diperTuan Muda, or Young Lord) who effectively controlled the Bugis half of the Kingdom. Riau can probably be considered part of Sumatra. The Bugis also established themselves in the Malayan states of Johore, Selangor (the Sultans there are both Bugis), and with strong influence in Kedah and Perak, possibly spilling into Terengganu. And of course, we have Bugis people in Singapore; some of our collector friends here are proudly Bugis.
The Bugis diaspora meant that there was a general division of the Sulawesi Bugis (which in itself had lots of sub-divisions), and the "Straits Bugis" who established themselves along the coasts of the Straits of Melaka. Bugis keris forging techniques infused itself well in the areas where they are found. In the South Malayan states, you would find more Bugis-type blades and the more North one travels, other non-Bugis forms start to appear (the most famous being the keris Pandai Saras and carita and melela kerises which probably have Javanese ancestry, but that is another discussion in itself.).
Here's an interesting read:
http://www.sabrizain.org/malaya/dutch3.htm