"Furniture" is an uncountable noun, so it doesn't typically take the plural form. Therefore, the correct phrase is "good furniture."
Uncountable nouns are not typically preceded by "a" or "an." Instead, they use determiners like "some," "any," or "this," or they appear without an article at all.
കൂടാതെ, "furniture" എന്നത് ഏകവചനമായതിനാൽ, "these" എന്നതിലുപരി "this" ആണ് ഉപയോഗിക്കാനുള്ള ശരിയായ demonstrative pronoun.