No, most definitely not possible.
First of all, Lord isn't a title. It's a style. It is held by a peer or the son of a Duke or Marquess (The Earl of Wessex would be Lord Wessex, for example).
There are websites that allow you to purchase a foot of land and become a Lord in Scotland - these are all scams. A genuine Laird is a titled land-owner in Scotland, but Laird isn't a title. It's just similar to Landlord. It's also not allowed for a Laird to call himself Lord, and to further add to the point, there can only ever be one Laird of an estate. The people buying these titles are not recognised by the Lord Lyon and he himself referred to them as worthless.
Any website you can find selling titles of nobility are scams. There are two types you could theoretically buy - a Lordship of the Manor or a Feudal Barony. A Lordship of a Manor is a half-extinct form of land ownership. If you owned the Manor of Surrey, for example, you were the Lord of the Manor of Surrey. In this form, Lord only refers to ownership. It isn't a title, your name would be "John Smith, Lord of the Manor of Surrey". These are around £5000
A Scottish feudal barony is also not able to give you the style or title of Lord. It is another form of land ownership, where the person's name would be John Smith, Baron of Skye. These are around £75,000 each. If you're feeling fancy you can buy an Earldom for around £250,000. These are much rarer, the latest to come up for sale was the Earldom of Arran.
Apart from these you cannot buy titles, especially not British peerages. They are forbidden from sale because of the Honours (Prevention of abuses act) 1925. Also, if you're American, you can't have any of these. US law dictates that:
"If any citizen of the United States shall accept, claim, receive or retain, any title of nobility or honour, or shall, without the consent of Congress, accept and retain any present, pension, office or emolument of any kind whatever, from any emperor, king, prince or foreign power, such person shall cease to be a citizen of the United States, and shall be incapable of holding any office of trust or profit under them, or either of them"
EDIT: Regal Titles is a scam. If you want to pay someone for a worthless piece of paper whilst dismissing detailed advice then you're perfectly welcome to. Clearly you don't know much about them, so if you're going to ignore advice from someone that does you're an idiot.